Means for obtaining thin liquid dross in electric furnaces for metallurgical purposes.



No. 877,739. PATEN'I'ED JAN. 28, 1908. H. RUHLING W. RODENHAUSER. MEANS EUR OBTAINING THIN LIQUID DROSS IN ELECTRIC FURNAGES y EGR METALLURGICAL PURPOSES. l

APPLIUATION FILED SEPT.7,1906.

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HERMANN RCHLING AND WILHELM RoDENHAUsER, oE vLKLiNGEN-oN-THE-SAAR GERMANY.

MEANS FOR OBTAINING- THIN LIQUID DROSS IN ELECTRIC FURNACES FOR METALLURGICAL PURPOSES.

Specification of Letters Patent.

Patented J an. 28, 1908.

Application fried september 7.1906. serial No. 333.688.

To all whom it may concern:

Be it known that we, HERMANN RCHLING, manufacturer, and WILHELM RonENHAUsER, engineer, subjects of the German Emperor, residing at Vlklingen-on-the-Saar, yin the inpire of Germany, have invented new and useful Improvements in Means for Obtaining Thin Liquid Dross in Electric Furnaces for Metallurgical Purposes, of which the followingis a specification.

The present invention relates to electric furnaces used for metallurgical purposes. and an important object is improved means for obtaining thin liquid dross in said furnaces.

`In obtaining metals from their ores, in refining iron, and in similar metallurgical processes, it. is of considerable importance not only 4for the course of the process, but also for the quality of the desired products, that the dross, slag or the like be obtained'in as hot and thin'liquid state as possible. The

ties 4in the case of electric furnaces, because the supply of current from and to the electrodes is influenced in aliigh degree by the contact with the dross. For the purpose of overcoming this objection it has already been proposed to let the electrodes of the secondary circuit end above the \mass of dross, so that. the take its path from the electrode through an air-gap and through the layer of dross. demand however, a uselessly high consumption of energy, and also very heavy demands are put upon the electrodes.

The present invention relates to an arrangement whereby the electric current serving for the fusion of the material to be s'melted, is compelled at certain points in the smelting space, to pass exclusively through the stratum of slag on the surface, so that at these points the slag will be`highly heated and liquefied. This is effected by damlike projections of the floor in the smelting space. ith skilful operation of the furnace only the layer of slag stands above the floor proections, which in consequence is highly eated by thesecondary current.

The invention is shown in the accompanying drawingin which:

attainment of this aim offers special difhculsecondary current must Figure l is a horizontal section and Fig. 2 is a vertical section on line 2-2 of Fig. l. .As shown the transformer core c together with the winding s, p is set into the furnace itself in such manner that the smelting channels, d surround the branch of the transformer in circular form, and in which the portions of the smelting channels, lying between the two branches are expanded into a hearthlike chamber; in consequence of the inductive effect of the primary winding p of the transformer, there is excited in the known manner, in the material inclosed in the smeltingchannels, which represents a sort of secondary winding, an intensely powerful electric current, the energy of which being changed into heat, fuses the materials; in order also to impart to the material contained in the enlarged hearth, a., the heat re- 4quired for its fusion by means of the electrode plates e let into the wall of the furnace, a particularly strong current is caused to pass through the hearth which is likewise induced in the secondary coils located on the branch offthe transformer. The tap hole of the furnace is locatedin one ofv its longitudinal walls; the electrode let into this must therefore bev broken in the center as the drawing shows.

The damlike projections at the bottom, that are the object of the invention in question, are designated'g and h in the drawing. Their cross section is shown in Fig. 2. The bottom projections are so formed that their upper edge is. uniform with the dividing layer between the molten product and the slag, as may be seen in Fig. 2. VThe bottom projection g is in the hearth like expansion a o the smelting space, the bottom projections h are Adisposed in the smelting channels. The slit like opening inthe bottom projection g has for its object to permit the vexit of the molten material inclosed between the bottom projections g, 7i when the tap holle is opened.

I claim:

In an electric furnace of the ty e described, a smelting hearth, damlike ri ges g, 7L arranged within the smelting hearth and smelting channels d projecting upwards to such 2- ermee jedges gf lhe ridgels 1i15m, be lflush Wilthshe sutwo Subscribing Witnesses. aceotemeta at,wenmete inte furnace whereby the electric current heating 5 the metal bath is forced to aes at these places through the layer oi?l oss floating Witnesses: above the metal bath. l t BEssIE F. DUNLAP, In testimony whereof We have signed our LOUIS VANDORY.

a height above the bottom, that the top names to this specicationin thepresence of 

